The thesis is divided into six sections. The Introduction discusses the themes of the dissertation, notably fascism, anti-fascism and Britain in the 1940s. It reviews the existing literature and outlines the method used. The first chapter examines the legacy of the inter-war years and the impact of internment on the fascists. It analyses the British League of Ex-Servicemen and Women and the Mosley book clubs, which came together to form the Union Movement. The chapter ends in 1951 with Oswald Mosley's decision to leave Britain, a symbol of the failure of British fascism. The second chapter stresses the homogeneity of fascist thinking and the common possession of core ideas, including elitism, racism, and anti-socialism. It suggests that fascist parties also acted in a similar way, they glorified their leaders and encouraged anti-semitism and violence. The chapter argues that postwar fascism recruited especially well among members of the middle class. However, even within this group, only a tiny minority was attracted towards fascism. The third chapter examines the history of the non-fascist organisations, including Labour, the Communist Party and the 43 Group. The chapter also evaluates anti-fascist methods, which involved exposing the fascists, heckling their speakers and turning over fascist platforms. The fourth chapter describes the moment at which fascists and anti-fascists opposed each other in the street. It suggests that the various state agencies, including the police, the Home Office, the law departments and MI6, worked with fascism, or did nothing to prevent its growth. Finally, the Conclusion discusses the obstacles which the fascists faced, including the legacy of the war and the Holocaust, and the success of the Conservative Party after 1945. It also suggests that anti-fascism also played significant part in the fascists' defeat.